廣(guang)(guang)西那(nei)(nei)坡天(tian)(tian)坑(keng)群(qun)天(tian)(tian)坑(keng)群(qun),由(you)19個天(tian)(tian)坑(keng)組成,主要分布于廣(guang)(guang)西百色市那(nei)(nei)坡縣的城(cheng)廂鎮和龍(long)合鄉,系目前北回歸(gui)線以(yi)南發(fa)現的較大(da)天(tian)(tian)坑(keng)群(qun)。那(nei)(nei)坡天(tian)(tian)坑(keng)群(qun)大(da)部分天(tian)(tian)坑(keng)容積在百萬立方米以(yi)上,原始(shi)景(jing)觀保(bao)存完好,人為活(huo)動痕跡(ji)較少,天(tian)(tian)坑(keng)與地下(xia)河(he)及(ji)其洞穴系統相連(lian)。那(nei)(nei)坡天(tian)(tian)坑(keng)群(qun)形成于定業地下(xia)河(he)流域內,地下(xia)河(he)匯水面積486平方公(gong)里(li),地下(xia)河(he)總(zong)長60公(gong)里(li),落差292米。
這些天坑有(you)的發育于海(hai)拔1000多米的高(gao)原之上,有(you)的順著谷地(di)地(di)下(xia)河軌跡呈(cheng)串(chuan)珠狀分(fen)布。那坡天坑群(qun)的發現對完善(shan)天坑演(yan)化理論(lun)具有(you)重(zhong)要(yao)科學價(jia)值(zhi)。
那(nei)坡(po)天(tian)坑(keng)群保存有完好(hao)的原始(shi)植(zhi)被(bei)群落,如董(dong)(dong)棕(zong)(zong)、蛇(she)根草(cao)、爬樹龍(long)、香(xiang)木(mu)蓮(lian)、棕(zong)(zong)櫚樹等,其中(zhong)(zhong)國家二級(ji)保護植(zhi)物的董(dong)(dong)棕(zong)(zong)群落,林木(mu)均高在30米(mi)(mi)以上。天(tian)坑(keng)中(zhong)(zhong)央香(xiang)木(mu)蓮(lian)樹高50米(mi)(mi),僅次于大石(shi)圍(wei)天(tian)坑(keng)香(xiang)木(mu)蓮(lian)。